Sound synthesis programs found through genetic programming have gone through an 'optimisation' stage that removes redundant elements, then through a 'parametrise' stage that identifies up to five constants that, when modulated, yield clearly different sonic characteristics. Ranges are estimated for these parameters, and input is normalised to the interval [0, 1]; a simple UI can be used to explore these parameters. The next task is to understand how the parameters can be coupled and automatically modulated by other processes, while still remaining within interesting sonic spaces.

(another go, this time showing the right source code)